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One of the most viable approaches to getting a better understanding of this is to use comprehensive computer-based models, as we heard this morning. Without the aid of such models, we cannot even begin to track the important and complex interactions, and we use these models to sharpen our understanding of what the key factors are that guide the behavior of the planet.

As we heard this morning in the first panel this morning, these models bring together our scientific understanding of winds, and air pressure, oceanic currents, and eddies, temperature, salinity, water vapor, and clouds, solar, and infrared radiation, precipitation and evaporation, and the list goes on of the many factors that have to be integrated into these mathematical based models.

They allow us to connect the oceans to the atmosphere in turn to the land surface; to understand how sea ice and snow cover changes with time.

In view of the comments this morning, I thought it would be helpful to give some scales that current models are divided into grids or blocks that are roughly the size of the State of Wyoming or Utah. But they only allow us to understand the conditions on roughly the scale of maybe one-third to a half of our continent.

So the scale is still too large to get at some of these regional issues that are of such profound importance to all of us. They are also designed to resolve time scales of maybe season to interannual and maybe over decades to a few centuries.

It is imperative that we increase our ability to do finer-scale resolution and to better represent the total processes, but that will require, as we discussed, greater computational capabilities.

I think this morning we got a good idea of the current state of knowledge about these models. They do best at simulating largescale processes. They are not as good at smaller scale features, and they are better at temperature than they are at precipitation.

These models are the best tools to provide us the insight of what might happen to the planet if it is subjected to various levels of change in the emission of greenhouse gases, or aerosols, or other human activities.

It is also the tool we have to understand natural variability. The balance between these two are a central issue that we are addressing through the program.

In summary, Mr. Chairman, global climate models are a criminal component of our overall U.S. strategy to work with our colleagues abroad to be sure, but to more fully understand global scale climate variability.

In this context, the program is dedicated to providing the Nation with credible, state of the art, global modeling capability.

We thank you for the opportunity to join this hearing this afternoon and to participate in the dialogue and discussion.

Thank you.

Testimony of

Robert W. Corell, Ph. D.

Assistant Director for Geosciences,

National Science Foundation

and

Chairman,
Subcommittee on Global Change Research

at the hearing of the
Subcommittee on Energy and Environment,

Committee on Science
U.S. House of Representatives

November 16, 1995

CLIMATE CHANGE MODELING AND THE USGCRP

Mr. Chairman and members of the subcommittee:

My name is Robert W. Corell. I am Assistant Director for Geosciences at the National Science Foundation. I am here today because of my additional role as chairman of the interagency Subcommittee on Global Change Research (SGCR), which administers the U. S. Global Change Research Program (USGCRP) under the auspices of the Committee on the Environment and Natural Resources (CENR) of the National Science and Technology Council (NSTC)

The U. S. Global Change Research Program

SGCR Membership: The SGCR includes representatives of fifteen federal research agencies supporting scientific activities and several planning and oversight offices of the Executive Office of the

President.' While the SGCR coordinates the focused global change research contributions of these agencies in support of the USGCRP, the USGCRP also benefits from important contributions and efforts that are carried out for other primary purposes. A prime example is the data and information that USGCRP research projects can access for research purposes from satellites whose primary purpose is to support national and international weather and disaster forecast programs.

USGCRP Charter: To understand the role of global climate modeling and its tie to governmental policymaking, which is the subject of this hearing, it is essential to have an overall perspective on the USGCRP. The USGCRP was established by President Reagan as a Presidential Initiative and formalized by Congress through the Global Change Research Act of 1990 (P.L. 101-606). This law under which the USGCRP is organized defines its purpose as being "to provide for the development and coordination of a comprehensive and integrated United States research program which will assist the Nation and the world to understand, assess, predict, and respond to human-induced and natural process of global change." The law also defines global change as "changes in the global environment (including alterations in climate, land productivity, oceans or other water resources, atmospheric chemistry, and ecological systems) that may alter the capacity of the Earth to sustain life."

Global Change Research: This charter for the USGCRP thus makes clear that there is to be a broad scope and it is to consider the full set of issues dealing with actual and potential global environmental change. The USGCRP is to cover aspects that are of interest to many departments and agencies, and it is to support activities ranging from

Agencies and offices with representatives to the SGCR include the Department of Agriculture; the Department of Commerce (National Oceanic and Atmospheric Administration and the National Institute of Standards and Technology); the Department of Defense; the Department of Health and Human Services (National Institutes of Health); the Department of the Interior, the Department of State; the Department of Transportation; the Environmental Protection Agency; the National Aeronautics and Space Administration; the National Science Foundation; the Smithsonian Institution, the Tennessee Valley Authority; the intelligence community; and the Office of Science and Technology Policy, the Council of Economic Advisors, and the Office of Management and Budget of the Executive Office of the President. ? The USGCRP has been an endorsed initiative of all of the administrations since its establishment in 1989.

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fundamental research to research that expands the knowledge base upon which the Nation and world may be able to effectively respond or adapt. It is important to note at this point, however, that the USGCRP does not include research on new energy technologies, nor does it include support for research underpinning specific response policies, such as the Climate Change Action Plan. The USGCRP is designed to improve the base of fundamental understanding about what is happening and about what scientific research indicates might happen in the future, not to support the implementation of particular policies.

Global Change Research Objectives: Because global change is so broadly defined, the SGCR has developed a program that places special emphasis on improving the information base concerning five specific objectives:

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1. Seasonal to Interannual Climate Fluctuations and Related Events: To predict climate fluctuations and environmental interactions over seasons to years, particularly the irregular occurrence of the El Nino warmings that affect the tropical Pacific Ocean and thereby the weather in the tropics and southern and western United States, and elsewhere on the planet;

2. Climate Change Over the Next Few Decades: To understand and project changes in climate and the environment over decades to centuries, especially the climatic changes (from warming and cooling effects) and environmental consequences expected from increasing concentrations of greenhouse gases, aerosols, other human influences, and natural factors that control climate variability,

3. Stratospheric Ozone Depletion and Increased UV Radiation: To predict depletion of stratospheric ozone, resulting increases in UVradiation, and changes in tropospheric (lower atmosphere) chemistry that affect, among other aspects, the ability of the atmosphere to cleanse itself of pollutants;

4. Changes in Land Cover and In Terrestrial and Marine Ecosystems: To monitor and understand changes in land cover and in terrestrial and marine ecosystems, including changes in land use, deforestation, and desertification; and

5. Earth System Science: To sustain exploratory research that increases understanding of the complex behavior of the total Earth system, identifying potential surprises and ensuring that all factors are being considered.

This hearing is concerned primarily with research on the second of the five objectives, although it relates in some way to all five.

Global Change Research Streams: To pursue these intercoupled objectives, the USGCRP supports research of various types that contributes in varying degrees to all of these efforts. The research is generally subdivided into six research streams:

1. Observations of the Global System: The major fraction of funding for observations of the global system is designated for NASA's Earth Observing System of satellites. Also relevant are programs for surface-based observing of UV radiation, ecosystems, and critical facets of the Earth system. Interagency and international efforts are underway to move toward an integrated global observing system.

2. Documentation and Data Management: USGCRP agencies have organized the Global Change Data and Information System (GCDIS) to make available their many data sets for research and analysis. NASA'S EOSDIS is a major component of GCDIS, but all agencies are actively participating. Agency implementation plans are now going through the approval process.

3. Field Programs and Process Studies: Together with nations around the world and within the U.S., internationally coordinated research programs are underway to understand how such processes as cloud

There are three major internationally coordinated research programs, coordinating and
integrating the research efforts of literally tens of thousands of scientists, research specialists,
and research associates, and virtually all the nations of the world. The programs are: (i) The
World Climate Research Program (WCRP). (ii) The Intemational Geosphere-Biosphere
Programme (IGBP), and (ii) The Human Dimensions of Global Environmental Change
Programme (HDP). These Programs are all sponsored by the International Council of Scientific
Unions (ICSU), the international academy of Science. Further, the WCRP is co-sponsored by the
World Meteorological Organization (WMO) and the Intergovernmental Oceanographic
Commission (IOC). Finally, the HDP is co-sponsored by the Intemational Social Sciences
Council (ISSC).

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